Almaz Optics, Inc.
12 Chadsford Ct.  Marlton, NJ 08053, USA
Tel:  856 797-0491, Fax: 856 797-0228
e-mail: mail@almazoptics.com

 

































BARIUM FLUORIDE, BaF2

Barium Fluoride is used for optical windows, lenses and prisms particularly when transmission into the ultraviolet is desired. The transmission range is 0.2 m - 11 m. Transmission in the VUV is degraded by prolonged exposure to moist atmosphere, but it is not significantly degraded under high energy irradiation. Barium fluoride is less resistant to attack by water than Calcium Fluoride. Pronounced water attack occurs at 500 C, but the material can be used to 800 C in a dry environment. Barium fluoride is the most resistant fluoride to high energy radiation, but does not have VUV transmission of the other fluorides. The material is relatively hard but is highly sensitive to thermal shock. Maximum available size: 180 mm Dia x 40 mm Thk.



Main Properties

Chemical Formula BaF2
Crystal Class Cubic
Molecular Weight 175.36
Lattice Constant, 6.196
Density, g/cm3 (20 C) 4.89
Knoop Hardness, kg/mm2 82
Young's Modulus, GPa 53.05
Shear Modulus, GPa 25.4
Bulk Modulus, GPa 56.4
Apparent Elastic Limit, MPa 26.89
Poisson Ratio 0.343
Dielectric Constant for 2 x 106 Hz 7.33
Melting Temperature, K 1550
Specific Heat, cal/(g K) at 274 K 0.096
Thermal Conductivity, W/(m K) at 286 K 11.7
Thermal Expansion, 1/K at 300 K 19.9 x 10-6
Bandgap, eV 9.1
Solubility, g/100 g H2O 0.17

Refractive Index

Wavelength, m 0.26 0.30 0.36 0.48 0.85 3.24 5.14 6.50 8.00 8.60 9.20 9.80
Refractive Index 1.51 1.50 1.49 1.48 1.47 1.46 1.45 1.44 1.43 1.42 1.41 1.40